Methodological considerations in comparing access to Pre-emptive renal transplantation between SLE and other ESRD causes in the USRDS

Background: We compared pre-emptive transplant rates between SLE and non-SLE end-stage renal disease (ESRD) from the U.S. Renal Data System (USRDS) and investigated the potential influence of frequency matching and primary ESRD causes in the non-SLE group. Methods: 4830 adult SLE patients with incident ESRD from USRDS 2005–2009 were frequency matched by age, sex and race to 4830 patients with incident non-SLE ESRD. Multivariable logistic regression models were used to estimate the odds of pre-emptive transplantation in SLE and non-SLE, and with the non-SLE subgroups by primary ESRD cause. Results: The odds ratios (OR) of receiving a pre-emptive transplant were similar among non-SLE and SLE (referent group): OR = 1.18 (95% CI: 0.92, 1.50; p = 0.20). However, the ORs for receiving a pre-emptive transplant were 0.19 (95% CI: 0.08, 0.42) in type 2 diabetes ESRD, 0.42 (95% CI: 0.23, 0.75) for hypertension-associated ESRD, 1.67 (95% CI: 1.10, 2.54) in type 1 diabetes ESRD, and 2.06 (95% CI: 1.55, 2.73) for “other” ESRD. In contrast to non-SLE, younger SLE patients were less likely to receive a pre-emptive transplant than older SLE patients. Conclusion: The results of this study provide compelling evidence that major improvements need to be made in optimizing access to pre-emptive transplantation in SLE by addressing sociodemographic disparities and the unique challenges faced by SLE patients. Applying careful matching and selecting appropriate comparison groups in future studies may facilitate the development of effective strategies to address these barriers and to increase the number of pre-emptive renal transplants among SLE patients.